58 



excising of the discoloured patchcs with a large margin 

 uf the SLiiTounding tissues as the funguw mycélium had 

 been found outside the discolouration, or, if the spots 

 were too large, in superficially shaving them and exposing 

 the parts so treated to the drying effect of the sun. Ail 

 excised parts were to be burnt. 



The fact that after several years of canker-treatment 

 the disease had not diminished as much as he had ex- 

 pected, Carruthers believed to be due to the careless- 

 ness of many planters in carrying out the recommendations. 

 On fields of the Experimentalstation of Peradeniya, where 

 the treatment was carried out strenuously, a fall in the 

 percentage of diseased trees was attained from 96 7o in 

 May 1902 to 1.9 "/„ at the end of 1903. ') {') 



Meanwhile Wright had made the experiment of spraying 

 the pods with a mixture of sulphates ofcopper and lime. ^) 

 As it is however highly probable (as has already been 

 pointed out), that the disease of the pods is not canker, 

 but caused by Phytophtora, his favourable results do not 

 teach us anything about the treatment of canker, however 

 important they may be in other directions. 



In Java and the West Indies Carruthers' advice is also 

 followed. In the West Indies the wounds are, in addition, 



1) H. Wright. Circulars of the Royal Botanic Gardens, Ceyloii. 

 Vol. II. No. 18, 1904, p. 280. 



2) From Zehntners obaervations in Java and ours in the 

 Saramucca district it does not scera certain that this fall in the per- 

 centage is only due to the treatment. In Java Zehntner saw 

 the disease saddenly assume a violent cliaracter notwithstanding 

 that the most careful treatment ol' diseased trees had been applied 

 for two years. Hère where nothing at ail was done, the disease 

 disappeared almost completely. 



3) Circulars of the Royal Botan. Gardens, Ceylon. Vol. II, 

 No. 21, 190i. 



